Of course having GDDR5X can inflate that improvement, too, but man it's just hard to make a good prediction.
I think 50% over GM204 is a little pessimistic while 75% over GM204 is a little optimistic. That's a large performance gap target.
I am surprised to see you so pessimistic. Look at the performance increase from GTX560Ti to 680 and from 680 to 980. Let's look at 1440p resolution to isolate CPU limited benchmarks. For 680 I'll use 770 launch date since that eliminates many older titles and NV will have had time to provide updated drivers for 1+ year to Kepler. The same I'll do for 980 by using Titan X launch.
680 was
92% faster than 560Ti at 1440p
980 was
71% faster than 680 at 1440p
That means the only way for 1080 to be only 50% faster than 980 is if NV failed massively with Pascal, they lower TDP vs. 980, they purposely gimp it with lower clocks out of the box. If things go according to plan, 1080 should be at least 60-70% faster than 980 at 1440p.
Applying that to today:
980 = 67%
980Ti = 83%
1080 = 980 * 1.6x faster =
107%
107% / 83% =
29% faster than a reference 980Ti.
The chance of GP104 not delivering better price/performance than 980Ti with either 1070 or 1080 is close to 0%. Even if 1080 has just 40% increase in perf/watt, 980Ti will
still lose.
980 = 67% * 1.4x faster (complete low-ball of Pascal's potential) =
93.8%
I know people hate knowing their $650 980Ti is about to get obsoleted but it's happening. It happened with 570/580 ->670/680, it happened with 780/780Ti -> 970/980, and it will happen with 980Ti -> 1070/1080.
This forum is weird lately. Polaris 10 is being overhyped and GP104 is being underhyped. I don't get it. :sneaky:
The only explanation I have is AMD fans are trying to save face by not having GP104 steamroll Polaris 10 and AMD having nothing until Vega. OTOH, 980Ti/Titan X users are in denial that their card is about to get embarrassed in all metrics, the same way 970/980 made 780Ti look like outdated/overpriced and power hungry tech Day 1 of their release.
I can contemplate the idea that NV will leave headroom for GTX770 style refresh but that only means GP104 will have huge overclocking headroom. So if you are going to use the argument that NV will try to lowball clock speeds on early 1070/1080 cards, this will be easily fixed via OCing.
So what's the best time window to sell my two msi 6g 980tis ?
In my euro country they still cost 750€ on the cheapest shop..
Let's see what the leaks show closer to end of May. We may find out that NV is doing a hard launch May 31st-June 4th, or they may do a soft launch with retail cards shipping June 15th. IMO, 2 weeks before retail launch is the latest time to dump them. Do new gen cards appear almost immediately at launch in your country? If I had 980Ti SLI, I'd be putting them on sale May 15th already. The big downside is that for most of June may only have reference cards and AIBs might only release the better versions towards late of June. If you have a decent spare card you can borrow from a friend, I'd put them up on sale mid-May at the latest.
So if you hold onto GPUs for a few years, wait a little bit and get a better deal. Not hard to see GP104 as Titan X + 20% or so @ 150W. And if it's $549, its a better deal than any 980Ti.
Even if Pascal don't beat it in perf/$ immediately, 6 months later it will as new games come out and "Game Ready" drivers shift optimization to Pascal.
For those who don't think it will happen, just look carefully at the uarch and see that the Maxwell -> Pascal leap is actually quite different in the CC/SM per Warp Scheduler and Cache/Register layout. Optimizations for Pascal will neuter Maxwell/Kepler because its going to favour warp sizes of 64 (like GCN) and that leaves the older uarch at worse utilization and bandwidth efficiency.
Spot on. Don't forget that AIBs will go beyond 150-160W TDP and release factory pre-overclocked versions with another 10-20% performance boost. Remember GTX460 FTW? This goes way back.
Launch Pascal benches are not going to be indicative of its true performance relative to 980Ti because NV will not have fully optimized Pascal drivers, will not have fully abandoned Maxwell optimizations, and June 2016 PC games aren't going to be as graphically demanding as 2017-2018 PC games. We saw this scenario play out with 680 vs. 580, 980 vs. 780Ti.
My son needs a GPU for his 6700k rig he just built a couple weeks ago. Currently he's using a 7870 from his last rig to hold him over. Advised him to wait it out for now.
You could buy an EVGA 970 and just step-up in 90 days.